Body param: Whether to run the model response in the background. Learn more.
Body param: Context management configuration for this request.
Body param: The conversation that this response belongs to. Items from this conversation are prepended to input_items for this response request.
Input items and output items from this response are automatically added to this conversation after this response completes.
Body param: Specify additional output data to include in the model response. Currently supported values are:
web_search_call.action.sources: Include the sources of the web search tool call.code_interpreter_call.outputs: Includes the outputs of python code execution in code interpreter tool call items.computer_call_output.output.image_url: Include image urls from the computer call output.file_search_call.results: Include the search results of the file search tool call.message.input_image.image_url: Include image urls from the input message.message.output_text.logprobs: Include logprobs with assistant messages.reasoning.encrypted_content: Includes an encrypted version of reasoning tokens in reasoning item outputs. This enables reasoning items to be used in multi-turn conversations when using the Responses API statelessly (like when the store parameter is set to false, or when an organization is enrolled in the zero data retention program).Body param: Text, image, or file inputs to the model, used to generate a response.
Learn more:
A list of one or many input items to the model, containing different content types.
A message input to the model with a role indicating instruction following
hierarchy. Instructions given with the developer or system role take
precedence over instructions given with the user role. Messages with the
assistant role are presumed to have been generated by the model in previous
interactions.
Text, image, or audio input to the model, used to generate a response. Can also contain previous assistant responses.
A list of one or many input items to the model, containing different content types.
An image input to the model. Learn about image inputs.
A file input to the model.
The detail level of the file to be sent to the model. Use auto to let the system select the detail level; for GPT-5.6 and later models, auto uses high-quality rendering, which may increase input token usage. Use low for lower-cost rendering, or high to render the file at higher quality. Defaults to auto.
The role of the message input. One of user, assistant, system, or
developer.
Labels an assistant message as intermediate commentary (commentary) or the final answer (final_answer).
For models like gpt-5.3-codex and beyond, when sending follow-up requests, preserve and resend
phase on all assistant messages — dropping it can degrade performance. Not used for user messages.
A message input to the model with a role indicating instruction following
hierarchy. Instructions given with the developer or system role take
precedence over instructions given with the user role.
A list of one or many input items to the model, containing different content types.
An image input to the model. Learn about image inputs.
A file input to the model.
The detail level of the file to be sent to the model. Use auto to let the system select the detail level; for GPT-5.6 and later models, auto uses high-quality rendering, which may increase input token usage. Use low for lower-cost rendering, or high to render the file at higher quality. Defaults to auto.
The role of the message input. One of user, system, or developer.
An output message from the model.
The content of the output message.
A text output from the model.
The annotations of the text output.
A citation for a web resource used to generate a model response.
The status of the message input. One of in_progress, completed, or
incomplete. Populated when input items are returned via API.
Labels an assistant message as intermediate commentary (commentary) or the final answer (final_answer).
For models like gpt-5.3-codex and beyond, when sending follow-up requests, preserve and resend
phase on all assistant messages — dropping it can degrade performance. Not used for user messages.
The results of a file search tool call. See the file search guide for more information.
The status of the file search tool call. One of in_progress,
searching, incomplete or failed,
The results of the file search tool call.
Set of 16 key-value pairs that can be attached to an object. This can be useful for storing additional information about the object in a structured format, and querying for objects via API or the dashboard. Keys are strings with a maximum length of 64 characters. Values are strings with a maximum length of 512 characters, booleans, or numbers.
A tool call to a computer use tool. See the computer use guide for more information.
The status of the item. One of in_progress, completed, or
incomplete. Populated when items are returned via API.
A click action.
A click action.
A double click action.
A drag action.
Flattened batched actions for computer_use. Each action includes an
type discriminator and action-specific fields.
A click action.
A double click action.
A drag action.
The output of a computer tool call.
The results of a web search tool call. See the web search guide for more information.
An object describing the specific action taken in this web search call. Includes details on how the model used the web (search, open_page, find_in_page).
A tool call to run a function. See the function calling guide for more information.
The output of a function tool call.
Text, image, or file output of the function tool call.
An array of content outputs (text, image, file) for the function tool call.
An image input to the model. Learn about image inputs
A file input to the model.
The detail level of the file to be sent to the model. Use auto to let the system select the detail level; for GPT-5.6 and later models, auto uses high-quality rendering, which may increase input token usage. Use low for lower-cost rendering, or high to render the file at higher quality. Defaults to auto.
The unique ID of the function tool call output. Populated when this item is returned via API.
The unique ID of the function tool call generated by the model.
A message routed between agents.
Plaintext, image, or encrypted content sent between agents.
An image input to the model. Learn about image inputs
An update to the conversation’s response configuration. The configuration remains in effect for subsequent responses until it is replaced by another configuration update.
A description of the chain of thought used by a reasoning model while generating
a response. Be sure to include these items in your input to the Responses API
for subsequent turns of a conversation if you are manually
managing context.
A compaction item generated by the v1/responses/compact API.
A tool representing a request to execute one or more shell commands.
The streamed output items emitted by a shell tool call.
A tool call representing a request to create, delete, or update files using diff patches.
The streamed output emitted by an apply patch tool call.
A request for human approval of a tool invocation.
A response to an MCP approval request.
The output of a custom tool call from your code, being sent back to the model.
Body param: A system (or developer) message inserted into the model’s context.
When using along with previous_response_id, the instructions from a previous
response will not be carried over to the next response. This makes it simple
to swap out system (or developer) messages in new responses.
Body param: An upper bound for the number of tokens that can be generated for a response, including visible output tokens and reasoning tokens.
Body param: The maximum number of total calls to built-in tools that can be processed in a response. This maximum number applies across all built-in tool calls, not per individual tool. Any further attempts to call a tool by the model will be ignored.
Body param: Set of 16 key-value pairs that can be attached to an object. This can be useful for storing additional information about the object in a structured format, and querying for objects via API or the dashboard.
Keys are strings with a maximum length of 64 characters. Values are strings with a maximum length of 512 characters.
Body param: Model ID used to generate the response, like gpt-6-astra. OpenAI
offers a wide range of models with different capabilities, performance
characteristics, and price points. Refer to the model guide
to browse and compare available models.
Body param: Whether to allow the model to run tool calls in parallel.
Body param: The unique ID of the previous response to the model. Use this to
create multi-turn conversations. Learn more about
conversation state. Cannot be used in conjunction with conversation.
Body param: Reference to a prompt template and its variables. Learn more.
Body param: Used by OpenAI to cache responses for similar requests to optimize your cache hit rates. Replaces the user field. Learn more.
Body param: Options for prompt caching. Supported for gpt-5.6 and later models. By default, OpenAI automatically chooses one implicit cache breakpoint. You can add explicit breakpoints to content blocks with prompt_cache_breakpoint. Each request can write up to four breakpoints. For cache matching, OpenAI considers up to the latest 80 breakpoints in the conversation, without a content-block lookback limit. Set mode to explicit to disable the implicit breakpoint. The ttl defaults to 30m, which is currently the only supported value. See the prompt caching guide for current details.
Body param: Deprecated. Use prompt_cache_options.ttl instead.
The retention policy for the prompt cache. Set to 24h to enable extended prompt caching, which keeps cached prefixes active for longer, up to a maximum of 24 hours. Learn more.
This field expresses a maximum retention policy, while
prompt_cache_options.ttl expresses a minimum cache lifetime. The two
fields are independent and do not interact.
For gpt-5.5, gpt-5.5-pro, and future models, only 24h is supported.
For older models that support both in_memory and 24h, the default depends on your organization’s data retention policy:
24h.in_memory when prompt_cache_retention is not specified.Body param: Configuration options for reasoning models.
Body param: A stable identifier used to help detect users of your application that may be violating OpenAI’s usage policies. The IDs should be a string that uniquely identifies each user, with a maximum length of 64 characters. We recommend hashing their username or email address, in order to avoid sending us any identifying information. Learn more.
Body param: Specifies the processing type used for serving the request.
service_tier=fast or service_tier=priority parameter for Responses or Chat Completions. The response will show service_tier=priority regardless of if you specify service_tier=fast or priority in your request.gpt-5.6-sol; a response served through it will show service_tier=ultrafast.When the service_tier parameter is set, the response body will include the service_tier value based on the processing mode actually used to serve the request. This response value may be different from the value set in the parameter.
Body param: Whether to store the generated model response for later retrieval via API. Defaults to true when omitted. If set to true, response data will be stored for at least 30 days, subject to the data retention exceptions.
Body param: If set to true, the model response data will be streamed to the client as it is generated using server-sent events. See the Streaming section below for more information.
Body param: What sampling temperature to use, between 0 and 2. Higher values like 0.8 will make the output more random, while lower values like 0.2 will make it more focused and deterministic.
We generally recommend altering this or top_p but not both.
Body param: Configuration options for a text response from the model. Can be plain text or structured JSON data. Learn more:
Body param: How the model should select which tool (or tools) to use when generating
a response. See the tools parameter to see how to specify which tools
the model can call.
Body param: An array of tools the model may call while generating a response. You
can specify which tool to use by setting the tool_choice parameter.
We support the following categories of tools:
Body param: An integer between 0 and 20 specifying the maximum number of most likely tokens to return at each token position, each with an associated log probability. In some cases, the number of returned tokens may be fewer than requested.
Body param: An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10% probability mass are considered.
We generally recommend altering this or temperature but not both.
Body param: The truncation strategy to use for the model response.
auto: If the input to this Response exceeds
the model’s context window size, the model will truncate the
response to fit the context window by dropping items from the beginning of the conversation.disabled (default): If the input size will exceed the context window
size for a model, the request will fail with a 400 error.Body param: This field is being replaced by safety_identifier and prompt_cache_key. Use prompt_cache_key instead to maintain caching optimizations.
A stable identifier for your end-users.
Used to boost cache hit rates by better bucketing similar requests and to help OpenAI detect and prevent abuse. Learn more.